diff --git a/lib_com/ivas_tools_fx.c b/lib_com/ivas_tools_fx.c
index e334a8cda710a8f1b77644f9c9fdd5177922aa5d..a1b484f6db3d0b97aa836ee217f5c7cfeec73d16 100644
--- a/lib_com/ivas_tools_fx.c
+++ b/lib_com/ivas_tools_fx.c
@@ -606,7 +606,9 @@ Word64 dot_product_cholesky_fixed(
 {
     Word16 i, j;
     Word64 suma, tmp_sum;
+#ifndef OPT_MCT_ENC_V3_BE
     Word32 mul;
+#endif
     Word32 tmp;
     const Word32 *pt_x, *pt_A;
     pt_A = A;
@@ -621,12 +623,20 @@ Word64 dot_product_cholesky_fixed(
 
         FOR( j = 0; j <= i; j++ )
         {
+#ifdef OPT_MCT_ENC_V3_BE
+            tmp_sum = W_add( tmp_sum, Mpy_32_32( *pt_x++, *pt_A++ ) );
+#else
             mul = Mpy_32_32( *pt_x++, *pt_A++ );
             tmp_sum = W_add( tmp_sum, W_deposit32_l( mul ) );
+#endif
         }
 
+#ifdef OPT_MCT_ENC_V3_BE
+        tmp = W_shl_sat_l( tmp_sum, -4 ); // to make sure that the tmp_sum will not overflow
+#else
         tmp_sum = W_shr( tmp_sum, 4 ); // to make sure that the tmp_sum will not overflow
         tmp = W_extract_l( tmp_sum );
+#endif
         suma = W_mac_32_32( suma, tmp, tmp );
     }
 
diff --git a/lib_com/options.h b/lib_com/options.h
index 48d8593c8dce8115c797c9c7d4d6d06bad3390a1..90f1239d80f74e63a6f678ed46db56b1f316f2b9 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -79,6 +79,7 @@
 
 
 /* Note: each compile switch (FIX_1101_...) is independent from the other ones */
+#define OPT_MCT_ENC_V3_BE
 #define OPT_MCT_ENC_V3_NBE
 #define OPT_MCT_ENC_V2_BE
 #define OPT_BIN_REND_V2_NBE
diff --git a/lib_enc/analy_sp_fx.c b/lib_enc/analy_sp_fx.c
index 0d42e5ff219f881f2fed2fb8bfb20cf00e109df0..48ed114c714a04829f3e88aaf4d633c9368461d6 100644
--- a/lib_enc/analy_sp_fx.c
+++ b/lib_enc/analy_sp_fx.c
@@ -727,6 +727,9 @@ static void ivas_find_enr(
     Word32 min_ener;
     Word16 shift = 0;
     move16();
+#ifdef OPT_MCT_ENC_V3_BE
+    Word16 tmp_shift;
+#endif
 
     ptR = &data[1];         /* first real */
     ptI = &data[L_FFT - 1]; /* first imaginary */
@@ -756,13 +759,20 @@ static void ivas_find_enr(
 
     freq = BIN_FREQ_FX;
     move16();
+#ifdef OPT_MCT_ENC_V3_BE
+    tmp_shift = sub( -Q16, shift ); // 16 - shift - 32
+#endif
     FOR( i = 0; i < voic_band; i++ ) /* up to maximum allowed voiced critical band  */
     {
         band_ener = 0;
         move64();
         start_freq = freq;
         move16();
+#ifdef OPT_MCT_ENC_V3_BE
+        FOR( ; LE_32( freq, crit_bands_fx[i] ); )
+#else
         WHILE( LE_32( freq, crit_bands_fx[i] ) )
+#endif
         {
             /*
                *ptE = *ptR * *ptR + *ptI * *ptI;
@@ -795,7 +805,11 @@ static void ivas_find_enr(
             freq = add( freq, BIN_FREQ_FX );
         }
 
+#ifdef OPT_MCT_ENC_V3_BE
+        band[i] = W_shl_sat_l( band_ener, tmp_shift ); // *q_band
+#else
         band[i] = W_extract_h( W_shl( band_ener, sub( Q16, shift ) ) ); // *q_band
+#endif
         move32();
 
         band_energies[i] = band[i]; /* per band energy without E_MIN   */ // *q_band
@@ -820,7 +834,11 @@ static void ivas_find_enr(
             move64();
             start_freq = freq;
             move16();
+#ifdef OPT_MCT_ENC_V3_BE
+            FOR( ; LE_32( freq, crit_bands_fx[i] ); )
+#else
             WHILE( LE_32( freq, crit_bands_fx[i] ) )
+#endif
             {
                 /*
                   *Bin_E = *ptR * *ptR + *ptI * *ptI;
@@ -851,7 +869,11 @@ static void ivas_find_enr(
                 freq = add( freq, BIN_FREQ_FX );
             }
 
+#ifdef OPT_MCT_ENC_V3_BE
+            band[i] = W_shl_sat_l( band_ener, tmp_shift ); // *q_band
+#else
             band[i] = W_extract_h( W_shl_nosat( band_ener, sub( Q16, shift ) ) ); // *q_band
+#endif
             move32();
 
             band_energies[i] = band[i]; /* per band energy without E_MIN   */ // *q_band
diff --git a/lib_enc/igf_enc.c b/lib_enc/igf_enc.c
index 7da9fa6cfa2608c3c955f520764f18ce653a2ea5..0a01dfe6667897772df2872ff2d6089504db72c5 100644
--- a/lib_enc/igf_enc.c
+++ b/lib_enc/igf_enc.c
@@ -135,7 +135,11 @@ static Word16 IGF_getCrest_new_fx(
     {
         x = logSpec[i];
         move16();
+#ifdef OPT_MCT_ENC_V3_BE
+        x_eff = L_mac0( x_eff, x, x );
+#else
         x_eff = L_add( x_eff, L_mult0( x, x ) );
+#endif
 
         if ( GT_16( x, x_max ) )
         {
diff --git a/lib_enc/ivas_sns_enc_fx.c b/lib_enc/ivas_sns_enc_fx.c
index e74e2297c4fb0c7af7587e200d944308c10ef6b8..610f39b1b2f0610a24bd4764d3cfd61ee0dfa108 100644
--- a/lib_enc/ivas_sns_enc_fx.c
+++ b/lib_enc/ivas_sns_enc_fx.c
@@ -258,7 +258,7 @@ static Word16 sns_1st_cod_fx(
             }
 
             /* for second split shift by five bits to store both indices as one 10 bit value */
-            IF( EQ_16( split, 1 ) )
+            if ( EQ_16( split, 1 ) )
             {
                 index_split = shl( index_split, 5 );
             }
diff --git a/lib_enc/tcx_utils_enc_fx.c b/lib_enc/tcx_utils_enc_fx.c
index 6ce40b00e3de8307ef7e00fd28acc788b6ca0243..cd4c0729710d1cfbe6e20dc56291699d9f15bbbf 100644
--- a/lib_enc/tcx_utils_enc_fx.c
+++ b/lib_enc/tcx_utils_enc_fx.c
@@ -2725,15 +2725,15 @@ void tcx_noise_factor_ivas_fx(
                 IF( LE_16( nTransWidth, 3 ) )
                 {
                     tmp2 = sub( k, c1 );
-                    IF( tmp2 > 0 )
+                    if ( tmp2 > 0 )
                     {
                         n = L_msu( n, k, (Word16) 0x8000 );
                     }
-                    IF( tmp2 > 0 )
+                    if ( tmp2 > 0 )
                     {
                         n = L_mac( n, nTransWidth_1, (Word16) 0x8000 );
                     }
-                    IF( tmp2 <= 0 )
+                    if ( tmp2 <= 0 )
                     {
                         n = L_mac( n, int_sqr[k], c2 );
                     }
@@ -2741,15 +2741,15 @@ void tcx_noise_factor_ivas_fx(
                 ELSE
                 {
                     tmp2 = sub( k, 12 );
-                    IF( tmp2 > 0 )
+                    if ( tmp2 > 0 )
                     {
                         n = L_msu( n, k, (Word16) 0x8000 );
                     }
-                    IF( tmp2 > 0 )
+                    if ( tmp2 > 0 )
                     {
                         n = L_sub( n, 0x70000 );
                     }
-                    IF( tmp2 <= 0 )
+                    if ( tmp2 <= 0 )
                     {
                         n = L_mac( n, int_sqr[k], 1152 /*0.03515625f Q15*/ );
                     }
@@ -2777,7 +2777,7 @@ void tcx_noise_factor_ivas_fx(
         }
         ELSE /* current line is zero, so update pointers & segment sum */
         {
-            IF( LT_16( win, nTransWidth ) )
+            if ( LT_16( win, nTransWidth ) )
             {
                 win = add( win, 1 );
             }
@@ -2794,15 +2794,15 @@ void tcx_noise_factor_ivas_fx(
         IF( LE_16( nTransWidth, 3 ) )
         {
             tmp2 = sub( k, c1 );
-            IF( tmp2 > 0 )
+            if ( tmp2 > 0 )
             {
                 n = L_msu( n, k, (Word16) 0x8000 );
             }
-            IF( tmp2 > 0 )
+            if ( tmp2 > 0 )
             {
                 n = L_mac( n, nTransWidth_1, (Word16) 0x8000 );
             }
-            IF( tmp2 <= 0 )
+            if ( tmp2 <= 0 )
             {
                 n = L_mac( n, int_sqr[k], c2 );
             }
@@ -2810,15 +2810,15 @@ void tcx_noise_factor_ivas_fx(
         ELSE
         {
             tmp2 = sub( k, 12 );
-            IF( tmp2 > 0 )
+            if ( tmp2 > 0 )
             {
                 n = L_msu( n, k, (Word16) 0x8000 );
             }
-            IF( tmp2 > 0 )
+            if ( tmp2 > 0 )
             {
                 n = L_sub( n, 0x70000 );
             }
-            IF( tmp2 <= 0 )
+            if ( tmp2 <= 0 )
             {
                 n = L_mac( n, int_sqr[k], 1152 /*0.03515625f Q15*/ );
             }
@@ -3663,7 +3663,10 @@ Word16 tcx_res_Q_spec_ivas_fx(
     Word16 s, s2, lf_deemph_factor;
     Word16 c;
     Word32 thres;
-
+#ifdef OPT_MCT_ENC_V3_BE
+    Word16 cmp_1, cmp_2;
+    Word32 tmp32_1, tmp32_2;
+#endif
 
     /* Limit the number of residual bits */
     sqTargetBits = s_min( sqTargetBits, NPRM_RESQ );
@@ -3679,16 +3682,28 @@ Word16 tcx_res_Q_spec_ivas_fx(
     move16();
     s2 = sub( x_Q_e, 1 );
 
+#ifdef OPT_MCT_ENC_V3_BE
+    cmp_1 = sub( sqTargetBits, kMaxEstimatorUndershoot );
+    cmp_2 = s_min( NPRM_RESQ, add( sqTargetBits, kMaxEstimatorOvershoot ) );
+#endif
     FOR( i = 0; i < L_frame; i++ )
     {
+#ifdef OPT_MCT_ENC_V3_BE
+        IF( GE_16( bits, cmp_1 ) )
+#else
         IF( GE_16( bits, sub( sqTargetBits, kMaxEstimatorUndershoot ) ) )
+#endif
         {
             fac_m = 0;
             move16();
             fac_p = 0;
             move16();
 
+#ifdef OPT_MCT_ENC_V3_BE
+            IF( GE_16( bits, cmp_2 ) )
+#else
             IF( GE_16( bits, s_min( NPRM_RESQ, add( sqTargetBits, kMaxEstimatorOvershoot ) ) ) )
+#endif
             {
                 BREAK;
             }
@@ -3700,11 +3715,11 @@ Word16 tcx_res_Q_spec_ivas_fx(
         {
             tmp1 = L_add( x_orig[i], 0 );
             tmp2 = Mpy_32_16_1( x_Q[i], sqGain );
-            IF( s > 0 )
+            if ( s > 0 )
             {
                 tmp2 = L_shr( tmp2, s );
             }
-            IF( s < 0 )
+            if ( s < 0 )
             {
                 tmp1 = L_shl( tmp1, s );
             }
@@ -3721,11 +3736,11 @@ Word16 tcx_res_Q_spec_ivas_fx(
                 move16();
                 bits = add( bits, 1 );
 
-                IF( x_Q[i] > 0 )
+                if ( x_Q[i] > 0 )
                 {
                     tmp1 = L_mult( fac_m, lf_deemph_factor );
                 }
-                IF( x_Q[i] < 0 )
+                if ( x_Q[i] < 0 )
                 {
                     tmp1 = L_mult( fac_p, lf_deemph_factor );
                 }
@@ -3738,11 +3753,11 @@ Word16 tcx_res_Q_spec_ivas_fx(
                 move16();
                 bits = add( bits, 1 );
 
-                IF( x_Q[i] > 0 )
+                if ( x_Q[i] > 0 )
                 {
                     tmp1 = L_mult( fac_p, lf_deemph_factor );
                 }
-                IF( x_Q[i] < 0 )
+                if ( x_Q[i] < 0 )
                 {
                     tmp1 = L_mult( fac_m, lf_deemph_factor );
                 }
@@ -3755,12 +3770,17 @@ Word16 tcx_res_Q_spec_ivas_fx(
     /*Quantize zeroed-line of the spectrum*/
     c = sub( 21627 /*0.66f Q15*/, mult_r( sq_round, 21627 /*0.66f Q15*/ ) );
 
+#ifdef OPT_MCT_ENC_V3_BE
+    FOR( i = 0; ( i < L_frame ) && ( bits < ( sqTargetBits - 2 ) ); i++ )
+    {
+#else
     FOR( i = 0; i < L_frame; i++ )
     {
         IF( GE_16( bits, sub( sqTargetBits, 2 ) ) )
         {
             BREAK;
         }
+#endif
 
         test();
         test();
@@ -3777,8 +3797,15 @@ Word16 tcx_res_Q_spec_ivas_fx(
 
             tmp1 = Mpy_32_16_1( thres, sqGain );
 
+#ifdef OPT_MCT_ENC_V3_BE
+            tmp32_1 = L_shl( x_orig[i], sub( x_orig_e, shift_tmp ) );
+            tmp32_2 = L_shl( tmp1, sub( sqGain_e, shift_tmp ) );
+            IF( GT_32( tmp32_1, tmp32_2 ) )
+            {
+#else
             IF( GT_32( L_shl( x_orig[i], sub( x_orig_e, shift_tmp ) ), L_shl( tmp1, sub( sqGain_e, shift_tmp ) ) ) )
             {
+#endif
                 prm[bits] = 1;
                 move16();
                 bits = add( bits, 1 );
@@ -3790,7 +3817,11 @@ Word16 tcx_res_Q_spec_ivas_fx(
                 x_Q[i] = L_shl( thres, sub( 1, x_Q_e ) );
                 move32();
             }
+#ifdef OPT_MCT_ENC_V3_BE
+            ELSE IF( L_add( tmp32_1, tmp32_2 ) < 0 )
+#else
             ELSE IF( L_add( L_shl( x_orig[i], sub( x_orig_e, shift_tmp ) ), L_shl( tmp1, sub( sqGain_e, shift_tmp ) ) ) < 0 )
+#endif
             {
                 prm[bits] = 1;
                 move16();